1. Technical Field
This invention relates to a water distillation unit and more particularly to a compact and energy efficient water distillation unit.
2. Background Art
Water distillation is, of course, well known in the art, as are apparatuses which perform the distillation. A few such apparatuses are shown in, for example, U.S. Pat. Nos. 3,748,234, 4,002,538 and 4,260,461.
U.S. Pat. No. 4,260,461, which is incorporated herein by reference, discloses a known apparatus which includes a deaerator for deaerating feedwater, and an evaporator assembly for distilling the water including a tube bundle with a shell, a demister and a compressor. A heater assembly to aid in startup and to make up for heat losses is also often used with apparatuses of this type.
One problem with prior art distillation apparatuses has been heat losses. Since the distillation process requires fairly high operating temperatures (in excess of 200.degree. F.), such heat losses can significantly increase the energy usage of the apparatus. The various surfaces of prior art apparatuses have been insulated so as to somewhat reduce the heat loss problem, but insulating the many surfaces increases the manufacturing cost of the apparatuses.
Yet another problem with many prior art distillation apparatuses is that they occupy significant volume and floor space. Distillation apparatuses are, of course, commonly used on ocean-going ships and oil platforms at sea to produce the crew's needs of clean water from the plentiful seawater, and space is at a premium on such ships. Further, in the case of ships used for military purposes, the design of distillers to withstand the shock and vibration of under water explosions is also a problem.
The present invention is directed toward overcoming one or more of the problems as set forth above.